The Zod execution thing didn't bother me as much as the "Superman as Hamlet" mentality that seemed to run all through most of the late eighties and early ninties. "Oh, am I too alien to fit in on Earth?", "Am I worthy of the title of worlds greatest hero?", "Would Cat Grant still want me if she knew I was Superman?", "Will Lois ever appreciate me as Clark?"
Well, I don't know if that's necessarily a post-crisis innovation. Superman is a character that has a very rich inner life, and some of my favorite Pre-Crisis Superman stories have been ones where Superman experiences dilemmas and turmoil.
A major, major theme of Superman's characterization is him wondering if he is an alien interloper that does too much for humanity, for instance.
The pre-crisis Superman was way more obsessed with his alien heritage then his late eighties counterpart (even going so far as to worship the Kryptonian god Rao despite being raised on Earth) and he still didn't complain about being an outsider as much as this guy did!
Despite all the "Great Rao" exclamations, I never got a sense that Superman was at all seriously religious. He honored Kryptonian holidays, certainly, but that was out of pride and respect for his heritage instead of piety.
Like a great many characters that Schwartz oversaw, Superman always seemed scientific, too secular and rational, as opposed to being mystical and intuitive. The best example of this "Schwartz-effect" is the Barry Allen Flash.
Maggin saw Superman as a cosmic monotheist, and something about that rings true. The idea he belongs to ONE religion and one only seems at odds with his "citizen of the world" characterization.
Don't even get me started on the reduced power thing. The movie Superman may not have been able blow stars out, but at least he could still crush coal into diamond. The post-crisis Superman couldn't do either one!
The idea of Superman being low-powered sounds really good on paper, but in practice...the character just doesn't FEEL like Superman.
I do however, appreciate concessions to reality. For instance, Superman wearing a breathing mask for long trips in space. Superman is superpowerful, and can tolerate the hostile conditions in space easily...but he's still a living organism from a terrestrial planet.